Heat treatment of fasteners and joints is an important part of the production process. Controlling the temperature, time and atmosphere of the furnace determines the quality and functional reliability of the connections. The obtained mechanical properties of fasteners must comply with the range specified in the standard. If after the heat treatment, the desired hardness and tensile strength are not obtained, the product loses its optimal performance. Bolts and nuts of class 8.8 and above, and nuts of class 8 and above. All of them need heat treatment to achieve the specified mechanical properties. The type of heat treatment is known as quenching and tempering. Hardening occurs when certain steels are heated to a certain temperature that changes the structure of the steel. This is followed by quenching (rapid cooling) and immersing the steel in oil. The temperature required to transform the structure is 880-870°C but may fluctuate depending on the amount of carbon and alloying elements in the steel. The furnace atmosphere is controlled to reduce the amount of oxidation in the steel. After hardening, the steel is hard and brittle and needs a process called tempering to reduce the hardness and brittleness. Heating at a temperature of about 420-530 degrees Celsius reduces the hardness, and as a result, the brittleness also decreases and the desired toughness properties are obtained. Tempering is the final process, the product has now achieved the desired properties.
By using experienced engineers and personnel in this field, Carizan company has placed itself in the category of the best in this industry by having the desired hardware and software in order to control the heat treatment process of products and orders and to satisfy customers.